This invention is for a heavy duty belt conveyor especially designed for the transportation of coarse, lumpy material, particularly coarse, rough rock of diverse sizes and shapes, but the conveyor may, of course, be used for the transporation of other bulk materials. It will be herein described for its primary intended purpose but without limitation thereto.
Rock or like mineral deposits as quarried, for example, may comprise a heterogeneous mixture of chunks and pieces of irregular size and shape and some lumps are quite large and heavy, pieces that may be of the order of five feet in diameter or more through one section being not uncommon. Troughed belt conveyors are desirably used for transporting such material from one location to another and as now constructed the loaded belt is supported at intervals on fixed idler troughing rolls. The heavily loaded belt, moving from one idler roll to the next, is subjected to a succession of impacts which results in rapid deterioration of the belt and reduced idler life. This is accelerated with the severe bumping and jolting that occurs with the loading of the belt, as well as in transporting the heavy load, and especially large pieces of rock.
We are aware that some attempts have been made in Russia to overcome this problem, or at least relieve it by providing a succession of cars under the belt which cradle and support the loaded belt in place of the usual troughing rolls, but this is a cumbersome and costly expedient and provides no satisfactory relief for the initial impact of the rock being loaded onto the belt at the loading station or with the shifting of the load on the belt at the transition end of the conveyor where the belt lifts off the supporting cars to pass around the discharge pulley where unloading takes place, and provision for the return travel of the cars to the starting position and the operation thereof is an expensive necessity.